There are various scaled outdoor maps of cities, counties, mountains, and the like in the world as civilization is developing, and more precise and detailed outdoor maps are created using a satellite and a global positioning system (GPS) so that the outdoor maps are gradually utilized in more various fields.
In contrast, indoor maps, which may be used in factories, public facilities, hospitals, airports, and the like, are not widely used in actual life at the present time in spite of a variety of applicable fields. This is because there is no a satellite and/or a GPS installed indoor, which makes it impossible to precisely track a location needed to acquire precise map information and hence induces an increase of manufacturing costs for the indoor map.
Meanwhile, since the technology of representing the indoor environment and configuration thereof into a map is applicable to a variety of fields, much research and development is being widely conducted. Particularly, a technology of detecting positions of objects using a distance measuring sensor and of creating an environment map using the detected positions is mainly used. This is because the distance measuring sensor can provide precise information about objects within a very short time interval.
In order to create a precise environment map, the position information acquired by the distance measuring sensor must be determined by a precise correlation. However, since a device such as an indoor GPS and the like is insufficient to measure an absolute position, it is difficult to detect the position information acquired by the distance measuring sensor precisely, and thus much research and development has been conducted to overcome this problem.
A scan matching algorithm as one area of research and development has widely been handled in the academic world. The scan matching algorithm has been developed to overcome, through the use of a matching relationship between information acquired by the distance measuring sensor and an encoded information error that is generated when an object provided with a distance measuring sensor moves from a reference location to another location.
However, since the majority of the scan matching technologies hitherto place the focus on automatically creating a map, there are many exceptional cases in that most of the above-mentioned scan matching technologies cannot be actually used and quality of the created map is not good.
Moreover, the environment recognition technology of a robot does not compensate when the environment recognition is wrong or fails.